Automatic test equipment (ATE), which is often referred to as a “tester”, includes electronics for testing a device under test (“DUT”). One component of a tester is its interface. The interface brings-out instrument signals to a customer test fixture for a device to be tested. A challenge is to bring-out a number of signals having appropriate electrical signal fidelity at an appropriate cost.
Prior generation testers include an internal cable assembly to bring-out signals from an internal instrument card to a standard tester interface (to which a DUT connects). This is done for several reasons. For example, the cable interface provides a standard interface for customer applications, test fixtures, and calibration. The cable interface also helps address potential alignment issues between the instrument and a customer DUT board. The cable interface is also useful in addressing space transformation issues between the instrument pitch and the customer test fixture. Despite these attributes, there are some issues associated with use of a test head interface that uses only cables. For example, the cable interface can add impedance discontinuities at the coaxial cable terminations, which can impact signal fidelity. The cable length itself can also result in additional signal attenuation. Also, the cost of internal signal cables can be relatively high.